O papel modulador do gene AIRE - capes

Molecular Immunology 42 (2005) 1043–1048Hybridization signatures during thymus ontogeny reveals modulationof genes coding for T-cell signaling proteinsDanielle A.R. Magalhães a , Claudia Macedo a , Cristina M. Junta a , Stephano S. Mello b ,Márcia M.C. Marques a , Renato S. Cardoso a , Elza T. Sakamoto-Hojo b ,Eduardo A. Donadi c , Geraldo A.S. Passos a,d,∗a Molecular Immunogenetics Group, Department of Genetics, Faculty of Medicine, University of São Paulo (USP), 14040-900 Ribeirão Preto, SP, Brazilb Laboratory of Cytogenetics and Mutagenesis, Department of Genetics, Faculty of Medicine, USP, 14040-900 Ribeirão Preto, SP, Brazilc Department of Medicine, Faculty of Medicine, USP, 14040-900 Ribeirão Preto, SP, Brazild Discipline of Genetics (DMEF), Faculty of Dentistry, USP, 14040-900 Ribeirão Preto, SP, BrazilReceived 18 August 2004; accepted 29 September 2004Available online 23 November 2004AbstractNon-manipulated inbred mouse strains constitutes an interesting model-system for in vivo studies on thymus ontogeny due to the possibilityto observe the molecular events of the thymocyte maturation. In previous studies, using RT-PCR method, we have found that several immunesystem genes such as interleukins and MHC are differentially expressed during ontogeny of the thymus whose genes act as modulators ofT-cell differentiation. To determine which other genes are modulated on a large-scale basis, we measured the levels of mRNA expression inmouse fetal thymus (14–17 days of gestation) by hybridization with cDNA microarrays containing 1,576 cDNA sequences derived from theIMAGE MTB library. T-cell maturation was monitored by detection of the T-cell receptor beta TRBV8.1-BD2.1 rearranged DNA segment.Each developmental phase of thymus, displayed a characteristic expression profile, as evaluated by the Cluster and Tree-View softwares. Genesdifferentially and significantly expressed were selected on the basis of significance analysis of the microarray data (SAM program). With thereclustering of only significantly expressed genes, it was possible to characterize the phases of thymus ontogeny, based on the differentialprofile of expression. Our method provided the detection of genes implicated in the cell signaling, such as the hematopoietic cell signaltransducer gene, genes implicated in T-cell calcium influx (tyrosine phosphatase) and calcium signaling proteins (vesicle transport bindingprotein 3, proline rich Gla, casein kinase alpha 1 and Down syndrome homolog protein 1) and a gene important for the protein transport,including T-cell receptors chains, towards the cell membrane (Golgi SNAP receptor complex member 2). The results demonstrate that thecDNA microarray used to explore the gene expression was useful for understanding the modulation of several cell-signaling genes, includingthe calcium cascade pathway, which is important for individual stages of T-cell maturation and control of anergy during thymus ontogeny.© 2004 Elsevier Ltd. All rights reserved.Keywords: Thymus ontogeny; T-cell signaling; cDNA microarrays; Gene expression profiling; Cluster analysis1. IntroductionThe differentiation of thymocytes to mature T-cells occurswithin the fetal thymus and all developmental stages are distinguishableby their expression of combination of CD cellsurfacemarkers. This is a highly modulated phenomenon,∗ Corresponding author. Tel.: +55 16 602 3030; fax: +55 16 633 0069.E-mail address: passos@rge.fmrp.usp.br (G.A.S. Passos).whose central molecular machinery is formed by the recombinasecomplex (RAG-1 and RAG-2) directly implicated inthe V(D)J recombination of T-cell receptor gene segments(TRA, TRB, TRG and TRD) (Lefranc and Lefranc, 2001).The occurrence of the V(D)J reaction is important for triggeringthe maturation of T-cells and is also regulated by severalother gene products such as interleukins (Fink and McMahan,2000; Fugmann, 2002; Muegge et al., 1993; Sollof etal., 1997).0161-5890/$ – see front matter © 2004 Elsevier Ltd. All rights reserved.doi:10.1016/j.molimm.2004.09.031